﻿using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

public class DESEncrypt
{
    private static string DESKey = "Key123Ace#321Key";

    #region ========加密========
    /// <summary>
    /// 加密
    /// </summary>
    /// <param name="Text"></param>
    /// <returns></returns>
    public static string Encrypt(string Text)
    {
        return Encrypt(Text, DESKey);
    }
    #endregion

    #region ========解密========
    /// <summary>
    /// 解密
    /// </summary>
    /// <param name="Text"></param>
    /// <returns></returns>
    public static string Decrypt(string Text)
    {
        if (!string.IsNullOrEmpty(Text))
        {
            return Decrypt(Text, DESKey);
        }
        else
        {
            return "";
        }
    }
    //默认密钥向量 
    private static byte[] Keys = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F };
    /// <summary> 
    /// DES加密字符串 
    /// </summary> 
    /// <param name="encryptString">待加密的字符串</param> 
    /// <param name="encryptKey">加密密钥,要求为16位</param> 
    /// <returns>加密成功返回加密后的字符串，失败返回源串</returns> 
    public static string Encrypt(string encryptString, string encryptKey = "Key123Ace#321Key")
    {
        try
        {
            byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 16));
            byte[] rgbIV = Keys;
            byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
            var DCSP = Aes.Create();
            MemoryStream mStream = new MemoryStream();
            CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
            cStream.Write(inputByteArray, 0, inputByteArray.Length);
            cStream.FlushFinalBlock();
            return Convert.ToBase64String(mStream.ToArray());
        }
        catch (Exception ex)
        {
            return ex.Message + encryptString;
        }

    }
    /// <summary> 
    /// DES解密字符串 
    /// </summary> 
    /// <param name="decryptString">待解密的字符串</param> 
    /// <param name="decryptKey">解密密钥,要求为16位,和加密密钥相同</param> 
    /// <returns>解密成功返回解密后的字符串，失败返源串</returns> 
    public static string Decrypt(string decryptString, string decryptKey = "Key123Ace#321Key")
    {
        try
        {
            byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.Substring(0, 16));
            byte[] rgbIV = Keys;
            byte[] inputByteArray = Convert.FromBase64String(decryptString);
            var DCSP = Aes.Create();
            MemoryStream mStream = new MemoryStream();
            CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
            Byte[] inputByteArrays = new byte[inputByteArray.Length];
            cStream.Write(inputByteArray, 0, inputByteArray.Length);
            cStream.FlushFinalBlock();
            return Encoding.UTF8.GetString(mStream.ToArray());
        }
        catch (Exception ex)
        {
            return ex.Message + decryptString;
        }

    }
    #endregion
}

